Regeneration of Plantlet of Water Yam (Dioscorea oppositifolia L.) through In Vitro Culture from Nodal Segments

The present investigation was carried out with a view to regenerate plantlet of Dioscorea oppositifolia L through in vitro culture. Nodal vine segments from 45days old plants of field grown Dioscorea opositifolia were used is explants for initial culture. The explants were cultured on MS (Murashige and Skoog's, 1962) medium supplemented with different concentration and combination of cycokinines and auxines for primary shoot proliferation. The best shoot proliferation was observed in MS medium containing 2.0 mg-l KINETIN +1.0 mg-l BAP+0.5mg-l NAA + 100mg-l ascorbic acid where 90% of explants showed proliferation with highest rate of shoot multiplication (10.5 shoots per explant). For rooting, the in vitro micro shootlets were inoculated onto the half-strength MS has media supplemented with 2.0 mg/l NAA and rooting was more profuse with micro tubers in the base of the root primordia. Rooted shoots were transplanted in the green house for hardening and their survival race was 90% in the field condition.